山东青岛早白垩世遗迹化石和皱饰构造的指相意义

ICHNOFOSSILS AND WRINKLE STRUCTURES AS FACIES INDICATORS FROM THE LOWER CRETACEOUS IN QINGDAO, SHANDONG, EASTERN CHINA

山东日青威盆地青岛地区中生代断陷构造盆地沉积下白垩统龙旺庄组和灵山岛组碎屑岩。即墨东北部丁字湾剖面龙旺庄组发现陆相遗迹化石Skolithos和Thallassinoides两个属,在灵山岛剖面灵山岛组海相地层中可见微生物成因的皱饰构造。这些原地生物-沉积证据表明早白垩世海水并未完全退出青岛地区,日青威断陷盆地内同时存在陆相和海相沉积。

Early Cretaceous terrigenous depositional sequences are widely distributed from the Longwangzhuang and equivalent Lingshandao formations in the Rizhao-Qingdao-Weihai Sag Basin,Qingdao of Shandong Province,Eastern China.Ichnofossils Skolithos and Thalassinoides discovered from siltstones of the Longwangzhuang Formation at the Dingziwan section,Jimo are considered as indicators of a continental facies.Wrinkle structure as a kind of microbial induced sedimentary structure typically forming on the surface of sea floor was found from dark grey siltstones of the Lingshandao Formation respectively at the outcrop section and the Lingke-1 borehole in the Lingshan Island.Both in situ preserved biotic and sedimentary evidences illustrate that sea-water partly remained in the Qingdao area resulting in co-occurrence of Early Cretaceous marine and non-marine deposits in the Rizhao-Qingdao-Weihai Sag Basin.